A conventional automobile steering lock shown in FIG. 1 comprises a housing 1 associated with a body member 16 having a passage extending along an axis therethrough, and an elongate rod member 17 adapted to move in telescopic fashion in the passage of the body member 16 along the axis, a first hook 160 and a second hook 170 respectively secured to the body member and the rod member 17 for engaging from the inside two opposite portions of a steering wheel, a lock 14 deposited in a lock base 13 on an upper surface of the housing 1 for locking the rod member 17 stationary with respect to the body member at any of a plurality of positions.
The housing 1 contains locating means consisting of a spherical bearing 10, a spring 11 and a retainer 12 and a locking means consisting of a lock 14 and round locking member 140 with a flat portion 141 and an arcuate portion 142 to match the semicirular grooves 171. The housing 1 has a passageway 15 for the elongate rod member 17 to telescopically move therein. The body member 16 is fixed with a rear end of the housing 1 for the rod member 17 to extend therein also.
When locking this lock on a steering wheel, the lock 14 has to be rotated in advance with a key, forcing the arcuate portion 142 of the locking member 140 to engage in one of the grooves 171 as shown in Fig. 2. Then the rod member 17 is stopped immovable at a certain length. If the lock 14 is to be unlocked or to adjust the length of the length of the rod member relative to the steering wheel, the key has to be used again to rotate the lock 14 in counter direction, forcing the arcuate portion of the round locking member 140 to disengage from one of the grooves 171 of the rod member 17. Then the rod member 17 is free to move relative to the housing 1. Meanwhile, the flat portion 141 of the locking member 14 becomes parallel to the rod member 17, as shown in FIG. 3. The rod member 17 is then possible to move in or out in the body member 16 and can be locked at a proper length needed by the key rotating the lock 14, forcing the arcuate portion 142 of the locking member 140 engaging one of the grooves 171.
The above mentioned conventional lock has drawbacks as follows.
1. Inconvenient to use. Every time when the length of the rod member is to be altered, the key has to be used.
2. The rod member is liable to be moved by large force.
3. Bad anti-burglary. The hooks are possible to be pried open by a piece of metal bar.